After his master, Goomoonryong, destroys his ki-center, Shioon decides to leave the world of Murim for a normal life. But as the person who holds the Phoenix Medallion of the Sunwoo Clan, and the only disciple of the infamous Goomoonryong, the Murim world will not let Shioon leave so easily...

Note: Volumes 1 and 2 contain the gaiden "The Breaker: Martial Arts City".

The new English teacher, Chun-Woo, is not your ordinary teacher. Shioon, a victim of constant bullying, unexpectedly witnesses Chun-Woo's fighting prowess, and begs him to make him his disciple. Chun-Woo claims he can teach Shioon only if he is truly determined, and Shioon must put his life on the line to prove it. It turns out, however, that Chun-Woo and his powers are more than meets the eye. Shioon makes a grand entrance into the Murim (the hidden world of martial arts), and he is about to be taught by the best there is!

The Breaker series has 2 parts, of which "The Breaker" is Part 1 (vol 1-10) and "The Breaker: New Waves" is Part 2 (on-going).

An intricate story revolving around Han Bi Kwang, as he follows a hero's journey. Just throw in a historic setting, ancient weapons, and a riveting plotline, and you have one of the most highly-acclaimed manwha, a definite must-read.
Bi-Kwang and Hwa-Rin try in vain to shake off Sang Pil "Gold Cobra" Jin and his men, but, ultimately, they are forced to defend themselves. Unfortunately, Bi-Kwang and Hwa-Rin lose, and the Sword of the Flowers is taken from them.
Bi-Kwang and Hwa-Rin regroup, pursuing Sang Pil Jin in an effort to retrieve the sword, but then Sang Pil and his men learn that Bi-Kwang and Hwa-Rin aren't the only ones after them. Sang Pil's superior, Master Yoo, has learned that Sang Pil planned to keep the sword for himself, and has approached Shi-Yun, leader of the Black Serpents, for help.
The lives of Bi-Kwang, Hwa-Rin, Sang Pil Jin, and his men are all in danger, as Master Yoo and the Black Serpents join forces and search for the sword together.
P.S - This manhwa was made into a MMORPG.

"Now that I'm back, I won't allow my loved ones to die again!" The Shadow Labyrinth - the deadliest catastrophe humanity has ever known. Desir Arman, one of the six remaining survivors of mankind, is inside the Labyrinth. The six of them attempt to clear the final level of the Labyrinth but ultimately fail, and the world comes to an end. However, when Desir thought he would meet his demise, what appears before him is the world... thirteen years ago?! Desir is returned to the past, back to the time when he enrolled at the nation's finest magic academy, Havrion. He is reunited with his precious friends, and he is determined to change the past to save the world and his loved ones...! Three years remain before the emergence of the Shadow World! Change the past and gather powerful comrades to save mankind!(Source: MU)

Yang Jaesin always dreams the same dream of a woman telling him she'll be waiting. One day, he meets a mysterious fortune teller who tells him he cannot avoid destiny and leaves him with some advice: For the path he walks, Jaesin must keep with him "the eyes that can see the isolated truth."

(Source: MangaUpdates)